A prior art arrangement is shown and described hereinafter and has a number of disadvantages which will become apparent from the description hereinafter.
A search has revealed the following US patent references:
U.S. Pat. No. 5,329,259 Stengel, “Efficient Amplitude/Phase Modulation Amplifier”
U.S. Pat. No. 5,612,651 Chethik, “Modulating Array QAM Transmitter”
U.S. Pat. No. 5,659,272 Linguet, “Amplitude Modulation Method and Apparatus using Two Phase Modulated Signals”
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